[21: Available at State Department website: https://travel.state.gov/content/dam/visas/Statistics/Non-Immigrant-Statistics/RefusalRates/FY18.pdf]
[21: Beschikbaar op de website van het ministerie van Buitenlandse Zaken: https://travel.state.gov/content/dam/visas/Statistics/Non-Immigrant-Statistics/RefusalRates/FY18.pdf]